ETSI RRS - The Standardization Path to Next Generation Cognitive Radio Systems

This paper details the current work status of the ETSI Reconfigurable Radio Systems (RRS) Technical Committee (TC) and gives an outlook on the future evolution. While previous publications have presented an overview of ETSI RRS' main working axes related to i) Cognitive Radio System Aspects, ii) Radio Equipment Architecture (including a Cognitive Pilot Channel (CPC) proposal and a Functional Architecture (FA) for Management and Control of Reconfigurable Radio Systems), iii) Cognitive Management and Control and iv) Public Safety, this document focuses on latest progress related to UHF White Spaces work and the definition of an SDR Handset Architecture. In particular, it is outlined how Cognitive Radio principles can help to adapt existing and/or evolving Radio Standards, such as 3GPP Long Term Evolution, to a possible operation in UHF White Space bands

Feasibility of Photovoltaic Module Single-Diode Model Fitting to the Current–Voltage Curves Measured in the Vicinity of the Maximum Power Point for Online Condition Monitoring Purposes

Photovoltaic system condition monitoring can be performed via single-diode model fitting to measured current–voltage curves. Model parameters can reveal cell aging and degradation. Conventional parameter identification methods require the measurement of entire current–voltage curves, causing interruptions in energy production. Instead, partial curves measured near the maximum power point offer a promising option for online condition monitoring. Unfortunately, measurement data reduction affects fitting and diagnosis accuracy. Thus, the optimal selection of maximum power point neighbourhoods used for fitting requires a systematic analysis of the effect of data selection on the fitted parameters. To date, only one published article has addressed this issue with a small number of measured curves using symmetrically chosen neighbourhoods with respect to the maximum power. Moreover, no study has determined single-diode fit quality to partial curves constructed via other principles, e.g., as a percentage of the maximum power point voltage. Such investigation is justified since the voltage is typically the inverter reference quantity. Our work takes the study of this topic to a whole new scientific level by systematically examining how limiting the current–voltage curve measuring range to maximum power point proximity based on both power and voltage affects single-diode model parameters. An extensive dataset with 2400 measured curves was analysed, and statistically credible results were obtained for the first time. We fitted the single-diode model directly to experimental curves without measuring outdoor conditions or using approximations. Our results provide clear guidance on how the choices of partial curves affect the fitting accuracy. A significant finding is that the correct selection of maximum power point neighbourhoods provides promising real-case online aging detection opportunities

Fitting Procedure for PV Panel Measured Current-Voltage Characteristics

Current-voltage curve measurements are a potential tool for efficient monitoring and diagnosis of photovoltaic (PV) panels and systems. To determine indicators of aging, degradation and other such phenomena of PV panels, an attractive option is to fit an electrical model of the PV panels to measured data in order to detect changes. However, raw measurement data usually contains measurement noise and other factors that can distort the analysis. The fitting process is challenging for instance, by the fact that the measurement points are unevenly distributed on the current-voltage curve, being mainly clustered on the open-circuit region. This unintentional weight can distort the fit. To address these issues, the present paper introduces a procedure for fitting an electrical model of the PV panels to the measured current-voltage curves so as to alleviate the above problems. The proposed approach is a prerequisite for a reliable diagnosis of the PV system status.acceptedVersionPeer reviewe

A novel procedure for identifying the parameters of the single-diode model and the operating conditions of a photovoltaic module from measured current–voltage curves

Photovoltaic (PV) module measured current–voltage curves together with the mathematical single-diode model are potential tools for PV system condition monitoring. Changes in model parameters can reveal module degradation and aging. However, all the parameter values change with varying operating irradiance and temperature, so they should also be identified. Unfortunately, useful operating condition measurements are rarely available in PV power plants. Thus, it is necessary to identify both operating conditions and model parameters directly from measured current–voltage curves. Only one such method has been reported in literature, however, using approximate explicit equations. The present work proposes a novel fitting procedure that identifies both single-diode model parameters and PV module temperature and irradiance utilizing an iterative method instead of approximate equations, which guarantees accurate results. The procedure enables degradation and aging analyses using only the internal electrical current–voltage curve measurements of the inverter. The results showed that the identified irradiance and temperature accurately reproduced the measured ones in all outdoor conditions. The stable identification of other single-diode model parameters, of which series resistance is especially suitable for detecting aging, confirmed the functionality of the procedure for condition monitoring.publishedVersionPeer reviewe

Preprocessing of PV Panel Measured Current-Voltage Characteristics Before Curve Fitting

PV panel current-voltage curves provided by measurement devices usually suffer from noise and other inaccuracies such as uneven distribution of the measurement points. This might complicate the curve fitting process by deteriorating the fit quality and making the diagnosis based on the curve misleading. This paper provides a stepwise preprocessing method for PV panel measured current-voltage curves. The method improves the quality of the measured current-voltage characteristic data, which has been verified by examining its effects on the fitting process.acceptedVersionPeer reviewe

Low-complexity angle of arrival estimation of wideband signals using small arrays

When the signal to noise ratio is relatively high, the angle of arrival of the strongest signal can be estimated with a very simple method and a small 3-D sensor array. The differences in the arrival times of the wideband signal received by spatially separated sensors are estimated using the polarity coincidence correlation. These time differences, i.e. time delays, determine the angle of arrival. In this paper the effects of quantization of the time delays are studied. It is found out that this simple method gives comparable performance to the conventional, direct correlation based methods in the case of a relatively high signa

State of the Art in ETSI SDR and CR related Standardization and Preparation of Commercialization

This paper details the current work status of the ETSI Reconfigurable Radio Systems (RRS) Technical Committee (TC) and gives an outlook on the future evolution. In particular, Software Defined Radio (SDR) related study results are presented with a focus on SDR architectures for Mobile Devices (MD), such as mobile phones, etc., as well as for Reconfigurable Base Stations (RBS). For MDs, a novel architecture is presented enabling the usage of SDR principles in a mass market context. Cognitive Radio (CR) principles within ETSI RRS are concentrated on two topics, a Cognitive Pilot Channel (CPC) proposal and a Functional Architecture (FA) for Management and Control of Reconfigurable Radio Systems, including Dynamic Self-Organising Planning and Management, Dynamic Spectrum Management, Joint Radio Resource Management, etc. Finally, study results are indicated which are targeting a SDR/CR security framework.JRC.DG.G.6-Security technology assessmen

ETSI RRS - The Standardization Path to Next Generation Cognitive Radio Systems

This paper details the current work status of the ETSI Reconfigurable Radio Systems (RRS) Technical Committee (TC) and gives an outlook on the future evolution. While previous publications have presented an overview of ETSI RRS' main working axes related to i) Cognitive Radio System Aspects, ii) Radio Equipment Architecture (including a Cognitive Pilot Channel (CPC) proposal and a Functional Architecture (FA) for Management and Control of Reconfigurable Radio Systems), iii) Cognitive Management and Control and iv) Public Safety, this document focuses on latest progress related to UHF White Spaces work and the definition of an SDR Handset Architecture. In particular, it is outlined how Cognitive Radio principles can help to adapt existing and/or evolving Radio Standards, such as 3GPP Long Term Evolution, to a possible operation in UHF White Space bands